The dynamic backlight modulation technology is commonly used in the liquid crystal display (LCD) for controlling the backlight brightness, thereby saving energy and improving quality of image effects, such as picture contrast. Wherein, the dynamic backlight modulation technology mainly includes multi-zone dynamic backlight modulation and global backlight modulation.
By the multi-zone dynamic backlight modulation, a backlight module of a liquid crystal display is, divided into a plurality of backlight zones, wherein a backlight source is set for each backlight zone, and the brightness of each backlight zone can be individually driven and controlled. In the multi-zone dynamic backlight modulation technology, a global image of each frame of a video signal is divided into a plurality of zoned image data blocks corresponding to the backlight zones, and the grayscale data of the zoned image data blocks obtained are collected to obtain a backlight value of the backlight zones corresponding to the zoned image data blocks, wherein the backlight value of each backlight zone represents the brightness difference among their corresponding zoned image data blocks, such that the backlight brightness of a backlight zone is determined by the grayscale brightness of the image data block corresponding to the backlight zone, and a brightness change of a backlight zone reflects a grayscale brightness change of the image data block corresponding to the backlight zone.